This invention relates to portable data storage cartridges, and, more particularly, to devices for providing an indication with respect to such portable data storage cartridges.
Portable data storage cartridges provide convenient means for storing data which may be transported between uses. One example comprises automated data storage libraries which can contain large quantities of portable data storage cartridges on storage shelves and employ robot accessors to access a cartridge when needed and deliver the cartridge to a data storage drive or transfer station.
In some instances, data, once recorded on a data storage medium of a portable data storage cartridge, is intended to be archived and left unchanged. Hence, a xe2x80x9cwrite protectxe2x80x9d device is placed in the cartridge which may be adjusted to indicate whether the data storage medium is write enabled and can be erased and written over, or whether the data storage medium is write protected and is not to be erased, as detected by a switch at the data storage drive which accepts the cartridge. Examples of two-position xe2x80x9con-offxe2x80x9d write protect devices for magnetic tape media in which one position is the same as though no cartridge is present are illustrated in U.S. Pat. No. 4,320,421, Larson et al., U.S. Pat. No. 4,399,481, Loranger et al., U.S. Pat. No. 5,699,216, Doty, and U.S. Pat. No. 5,786,967, Gerfast et al. Gerfast et al. arranges the size of a recess and the write protect device such that separate a switch of the data storage drive for detecting the presence of a cartridge may also be utilized with the write protect switch to write protect magnetic tape having a different coercivity from being written by an older tape drive, and to selectively write protect the tape in a newer tape drive. Thus, Gerfast et al. provides a two position xe2x80x9con-offxe2x80x9d write protect, in which one position is the same as though no cartridge is present.
The tape of a magnetic tape data storage cartridge is a medium only and has no capability for providing processing capability. Hence, a write protect for the cartridge is useful to prevent mistaken erasure of important data stored on the medium in the cartridge.
The incorporated ""030 U.S. Patent Application illustrates a different type of portable data storage cartridge which comprises a data storage device, such as a magnetic disk drive, an optical disk drive, an electronic memory, etc., and the transfer station of the ""030 Application is arranged to distinguish between a magnetic tape cartridge and a cartridge having a data storage device. A data storage device comprises processing capability for the device, such that data may be stored by the device in an efficient manner without any need for a simple write protect for the entire portable data storage cartridge.
It would be advantageous to externally indicate information regarding a portable data storage cartridge, such as the type of device or medium located in the cartridge, or other characteristics of the cartridge, as well as write protection, if needed. Hence, it is an object of the present invention to provide a means for externally indicating various characteristics of portable data storage cartridges.
A multi-position mechanical indicator is provided for a portable data storage cartridge, the portable data storage cartridge having at least a data storage medium therein. Examples comprise a portable data storage cartridge having a data storage device, such as a magnetic disk drive, an optical disk drive, an electronic memory, etc., or a portable data storage cartridge having a medium without a device, such as a magnetic tape or an optical disk.
The portable data storage cartridge has a chamber closely adjacent an exterior wall of the cartridge and has an opening extending through the exterior wall to the chamber.
The indicator comprises a rotary device in the general form of at least one right cylindrical section having a central axis of rotation, and arranged to be rotatable in the chamber. A peripheral surface of the rotary device right cylindrical section has an encoded pattern of at least one cylindrical surface and of a plurality of facets interrupting the cylindrical surface(s). The facets are located at various axial positions in the direction of the of the central axis of rotation, and located at various angularly spaced rotational positions about the central axis of rotation. Thus, at differing rotational positions of the rotary device, at least one or none of the facets is positioned at the exterior wall opening of the portable data storage cartridge. In one embodiment of the present invention, the facets of the encoded pattern are parallel to the central axis of rotation of the rotary device, such that they and the cylindrical surfaces interact with switches to provide the desired indications.
In one embodiment of the present invention, at least one retaining element is provided on the rotary device for interacting with at least one matching retaining element of the cartridge to retain the rotary device in at least one of the rotary positions. In one example, the rotary device retaining element comprises at least one detent, and the matching retaining element of the cartridge comprises a plurality of indentations in the cartridge chamber, such that the rotary device retaining element detent(s) may rest in any of the plurality of indentations. In another example, the rotary device retaining element comprises a plurality of indentations, and the matching retaining element of the cartridge comprises at least one detent which may rest in any of the plurality of indentations.
In either example, a spring may urge the detent(s) into the indentations. Alternatively, in the first example, the rotary device retaining element detent comprises a resilient material, and the rotary device is arranged to fit within the chamber of the cartridge with a compression force thereon when the rotary device retaining element detent(s) is out of all of the plurality of indentations in the cartridge chamber, also urging the detent(s) into the indentations. In the second example, the rotary device may comprise a resilient material, and the rotary device is arranged to fit within the chamber of the cartridge with a compression force thereon when the detent(s) is out of all of the plurality of indentations of the rotary device, also urging the detent(s) into the indentations.
In one embodiment, a cylindrical section of larger diameter than the cylindrical surface is provided, comprising a thumb wheel for rotating the rotary device in the chamber of the cartridge. The thumb wheel cylindrical section comprises a roughened surface for engaging the thumb wheel.
A facet comprises a flat or concave surface such that the radius of a facet from the central axis of rotation is substantially less than that of a cylindrical surface.
In one embodiment of the present invention, the facets of the encoded pattern are parallel to the central axis of rotation of the rotary device, such that they and the cylindrical surfaces interact with switches to provide the desired indications, the cylindrical surface comprising a xe2x80x9c1xe2x80x9d and activating a switch, and a facet comprising a xe2x80x9c0xe2x80x9d and not activating a switch. In accordance with an aspect of the present invention, no all xe2x80x9c0xe2x80x9d or all facet code is utilized, such that a switch is always activated when a cartridge is present, serving as a presence indicator, indicating that the cartridge is fully loaded.
For a fuller understanding of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.